Bulk Data Movement Guide

10.5.2
- 10.5.6
- 10.5.5
- 10.5.4
- 10.5.3
- 10.5.1
- 10.5
- 10.4.1
- 10.4.0 HotFix 1
- 10.4.0

Back Next

Configuring Data Maps Caching - Example

In this example, you enable data maps caching and configure a maximum size of 20 MBs for the data maps cache, which is large enough to hold 20 large IDMS data maps or thousands of small data maps.

Verify that the REGION size specified in the DTLLST step in the JCL is large enough to run the PowerExchange Listener job. For example, if you define DMXCACHE_MAX_MEMORY_MB=20, you might have to increase the REGION size by 20 MBs.

To enable data maps caching and to configure a data maps cache size of 20 MBs, define the following statement in the DBMOVER configuration file:

DMXCACHE_MAX_MEMORY_MB=20

Based on your environment, configure PowerExchange to run data maps caching in single-job or multiple-jobs mode.

The following table describes the environment and configuration steps for each mode:

Environment	Mode	Configuration Steps
You use one PowerExchange Listener job and no netport jobs.	Single-job mode	Define the following DBMOVER configuration statement: DMXCACHE_MULTIPLEJOBS=N In this situation, the default cache size is sufficient. Default is N. For more information about single-job mode, see Single-Job Mode.
You use multiple PowerExchange Listener or netport jobs to access the same data maps file.	Multiple-jobs mode	Define the following DBMOVER configuration statement: DMXCACHE_MULTIPLEJOBS=Y Additionally, if you want PowerExchange to free the ECSA memory when the PowerExchange Listener closes, define the following DBMOVER configuration statement: DMXCACHE_DELETEECSA=Y However, because shared memory allocation is a complex task and 4096 bytes of memory is a small amount, you can accept the default value, which is N, to permanently retain the ECSA memory. For more information about multiple-jobs mode, see Multiple-Jobs Mode.

Optionally, if you run data maps caching in multiple-jobs mode, you can run the PWXUDMX utility to view the ECSA memory.

For more information about the PWXUDMX utility, see the

PowerExchange Utilities Guide

To determine if data maps caching improved performance, close the PowerExchange Listener and review messages in the PowerExchange log.

Rename Saved Search

Table of Contents

Bulk Data Movement Guide

Bulk Data Movement Guide

Configuring Data Maps Caching - Example

Configuring Data Maps Caching - Example